From the Find group on the Home tab, select Address Book.
In the Address Book window that appears, from the Tools menu, select Options... .
Under "When opening the address book, show this address list first:", use the scroll-down menu to select the appropriate listing (i.e., Global Address Book, or Outlook Address Book).
To save the changes, click OK.
To close the Address Book, click the X in the top right corner.
Outlook 2007 and 2003
From the Tools menu, select Address Book... .
In the Address Book window that appears, from the Tools menu, select Options... .
Under "Show this address list first:", use the scroll-down menu to select the appropriate listing (i.e., Personal Address Book, Global Address Book, or Outlook Address Book).
Outlook 2010
Outlook 2007 and 2003